/*

 * QPAK support routines for PhysicsFS.

 *

 *  This archiver handles the archive format utilized by Quake 1 and 2.

 *  Quake3-based games use the PkZip/Info-Zip format (which our zip.c

 *  archiver handles).

 *

 *  ========================================================================

 *

 *  This format info (in more detail) comes from:

 *     http://debian.fmi.uni-sofia.bg/~sergei/cgsr/docs/pak.txt

 *

 *  Quake PAK Format

 *

 *  Header

 *   (4 bytes)  signature = 'PACK'

 *   (4 bytes)  directory offset

 *   (4 bytes)  directory length

 *

 *  Directory

 *   (56 bytes) file name

 *   (4 bytes)  file position

 *   (4 bytes)  file length

 *

 *  ========================================================================

 *

 * Please see the file LICENSE.txt in the source's root directory.

 *

 *  This file written by Ryan C. Gordon.

 */

#if (defined PHYSFS_SUPPORTS_QPAK)

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

/* !!! FIXME: what is this here for? */

#if 1  /* Make this case insensitive? */

#define QPAK_strcmp(x, y) __PHYSFS_stricmpASCII(x, y)

#define QPAK_strncmp(x, y, z) __PHYSFS_strnicmpASCII(x, y, z)

#else

#define QPAK_strcmp(x, y) strcmp(x, y)

#define QPAK_strncmp(x, y, z) strncmp(x, y, z)

#endif

typedef struct

{

    char name[56];

    PHYSFS_uint32 startPos;

    PHYSFS_uint32 size;

} QPAKentry;

typedef struct

{

    PHYSFS_Io *io;

    PHYSFS_uint32 entryCount;

    QPAKentry *entries;

} QPAKinfo;

typedef struct

{

    PHYSFS_Io *io;

    QPAKentry *entry;

    PHYSFS_uint32 curPos;

} QPAKfileinfo;

/* Magic numbers... */

#define QPAK_SIG 0x4b434150   /* "PACK" in ASCII. */

static inline int readAll(PHYSFS_Io *io, void *buf, const PHYSFS_uint64 len)

{

    return (io->read(io, buf, len) == len);

} /* readAll */

static void QPAK_dirClose(dvoid *opaque)

{

    QPAKinfo *info = ((QPAKinfo *) opaque);

    info->io->destroy(info->io);

    allocator.Free(info->entries);

    allocator.Free(info);

} /* QPAK_dirClose */

static PHYSFS_sint64 QPAK_read(PHYSFS_Io *io, void *buffer, PHYSFS_uint64 len)

{

    QPAKfileinfo *finfo = (QPAKfileinfo *) io->opaque;

    const QPAKentry *entry = finfo->entry;

    const PHYSFS_uint64 bytesLeft = (PHYSFS_uint64)(entry->size-finfo->curPos);

    PHYSFS_sint64 rc;

    if (bytesLeft < len)

        len = bytesLeft;

    rc = finfo->io->read(finfo->io, buffer, len);

    if (rc > 0)

        finfo->curPos += (PHYSFS_uint32) rc;

    return rc;

} /* QPAK_read */

static PHYSFS_sint64 QPAK_write(PHYSFS_Io *io, const void *b, PHYSFS_uint64 len)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, -1);

} /* QPAK_write */

static PHYSFS_sint64 QPAK_tell(PHYSFS_Io *io)

{

    return ((QPAKfileinfo *) io->opaque)->curPos;

} /* QPAK_tell */

static int QPAK_seek(PHYSFS_Io *io, PHYSFS_uint64 offset)

{

    QPAKfileinfo *finfo = (QPAKfileinfo *) io->opaque;

    const QPAKentry *entry = finfo->entry;

    int rc;

    BAIL_IF_MACRO(offset >= entry->size, ERR_PAST_EOF, 0);

    rc = finfo->io->seek(finfo->io, entry->startPos + offset);

    if (rc)

        finfo->curPos = (PHYSFS_uint32) offset;

    return rc;

} /* QPAK_seek */

static PHYSFS_sint64 QPAK_length(PHYSFS_Io *io)

{

    const QPAKfileinfo *finfo = (QPAKfileinfo *) io->opaque;

    return ((PHYSFS_sint64) finfo->entry->size);

} /* QPAK_length */

static PHYSFS_Io *QPAK_duplicate(PHYSFS_Io *_io)

{

    QPAKfileinfo *origfinfo = (QPAKfileinfo *) _io->opaque;

    PHYSFS_Io *io = NULL;

    PHYSFS_Io *retval = (PHYSFS_Io *) allocator.Malloc(sizeof (PHYSFS_Io));

    QPAKfileinfo *finfo = (QPAKfileinfo *) allocator.Malloc(sizeof (QPAKfileinfo));

    GOTO_IF_MACRO(retval == NULL, ERR_OUT_OF_MEMORY, QPAK_duplicate_failed);

    GOTO_IF_MACRO(finfo == NULL, ERR_OUT_OF_MEMORY, QPAK_duplicate_failed);

    io = origfinfo->io->duplicate(origfinfo->io);

    GOTO_IF_MACRO(io == NULL, NULL, QPAK_duplicate_failed);

    finfo->io = io;

    finfo->entry = origfinfo->entry;

    finfo->curPos = 0;

    memcpy(retval, _io, sizeof (PHYSFS_Io));

    retval->opaque = finfo;

    return retval;

QPAK_duplicate_failed:

    if (finfo != NULL) allocator.Free(finfo);

    if (retval != NULL) allocator.Free(retval);

    if (io != NULL) io->destroy(io);

    return NULL;

} /* QPAK_duplicate */

static int QPAK_flush(PHYSFS_Io *io) { return 1;  /* no write support. */ }

static void QPAK_destroy(PHYSFS_Io *io)

{

    QPAKfileinfo *finfo = (QPAKfileinfo *) io->opaque;

    finfo->io->destroy(finfo->io);

    allocator.Free(finfo);

    allocator.Free(io);

} /* QPAK_destroy */

static const PHYSFS_Io QPAK_Io =

{

    QPAK_read,

    QPAK_write,

    QPAK_seek,

    QPAK_tell,

    QPAK_length,

    QPAK_duplicate,

    QPAK_flush,

    QPAK_destroy,

    NULL

};

static int qpakEntryCmp(void *_a, PHYSFS_uint32 one, PHYSFS_uint32 two)

{

    if (one != two)

    {

        const QPAKentry *a = (const QPAKentry *) _a;

        return QPAK_strcmp(a[one].name, a[two].name);

    } /* if */

    return 0;

} /* qpakEntryCmp */

static void qpakEntrySwap(void *_a, PHYSFS_uint32 one, PHYSFS_uint32 two)

{

    if (one != two)

    {

        QPAKentry tmp;

        QPAKentry *first = &(((QPAKentry *) _a)[one]);

        QPAKentry *second = &(((QPAKentry *) _a)[two]);

        memcpy(&tmp, first, sizeof (QPAKentry));

        memcpy(first, second, sizeof (QPAKentry));

        memcpy(second, &tmp, sizeof (QPAKentry));

    } /* if */

} /* qpakEntrySwap */

static int qpak_load_entries(QPAKinfo *info)

{

    PHYSFS_Io *io = info->io;

    PHYSFS_uint32 fileCount = info->entryCount;

    QPAKentry *entry;

    info->entries = (QPAKentry*) allocator.Malloc(sizeof(QPAKentry)*fileCount);

    BAIL_IF_MACRO(info->entries == NULL, ERR_OUT_OF_MEMORY, 0);

    for (entry = info->entries; fileCount > 0; fileCount--, entry++)

    {

        BAIL_IF_MACRO(!readAll(io, &entry->name, 56), NULL, 0);

        BAIL_IF_MACRO(!readAll(io, &entry->startPos, 4), NULL, 0);

        BAIL_IF_MACRO(!readAll(io, &entry->size, 4), NULL, 0);

        entry->size = PHYSFS_swapULE32(entry->size);

        entry->startPos = PHYSFS_swapULE32(entry->startPos);

    } /* for */

    __PHYSFS_sort(info->entries, info->entryCount, qpakEntryCmp, qpakEntrySwap);

    return 1;

} /* qpak_load_entries */

static void *QPAK_openArchive(PHYSFS_Io *io, const char *name, int forWriting)

{

    QPAKinfo *info = NULL;

    PHYSFS_uint32 val = 0;

    PHYSFS_uint32 pos = 0;

    PHYSFS_uint32 count = 0;

    assert(io != NULL);  /* shouldn't ever happen. */

    BAIL_IF_MACRO(forWriting, ERR_ARC_IS_READ_ONLY, 0);

    BAIL_IF_MACRO(!readAll(io, &val, 4), NULL, NULL);

    BAIL_IF_MACRO(PHYSFS_swapULE32(val) != QPAK_SIG, ERR_NOT_AN_ARCHIVE, NULL);

    BAIL_IF_MACRO(!readAll(io, &val, 4), NULL, NULL);

    pos = PHYSFS_swapULE32(val);  /* directory table offset. */

    BAIL_IF_MACRO(!readAll(io, &val, 4), NULL, NULL);

    count = PHYSFS_swapULE32(val);

    /* corrupted archive? */

    BAIL_IF_MACRO((count % 64) != 0, ERR_CORRUPTED, NULL);

    count /= 64;

    BAIL_IF_MACRO(io->seek(io, pos), NULL, NULL);

    info = (QPAKinfo *) allocator.Malloc(sizeof (QPAKinfo));

    BAIL_IF_MACRO(info == NULL, ERR_OUT_OF_MEMORY, NULL);

    memset(info, '\0', sizeof (QPAKinfo));

    info->io = io;

    info->entryCount = count;

    if (!qpak_load_entries(info))

    {

        if (info->entries != NULL)

            allocator.Free(info->entries);

        allocator.Free(info);

        return NULL;

    } /* if */

    return info;

} /* QPAK_openArchive */

static PHYSFS_sint32 qpak_find_start_of_dir(QPAKinfo *info, const char *path,

                                            int stop_on_first_find)

{

    PHYSFS_sint32 lo = 0;

    PHYSFS_sint32 hi = (PHYSFS_sint32) (info->entryCount - 1);

    PHYSFS_sint32 middle;

    PHYSFS_uint32 dlen = strlen(path);

    PHYSFS_sint32 retval = -1;

    const char *name;

    int rc;

    if (*path == '\0')  /* root dir? */

        return 0;

    if ((dlen > 0) && (path[dlen - 1] == '/')) /* ignore trailing slash. */

        dlen--;

    while (lo <= hi)

    {

        middle = lo + ((hi - lo) / 2);

        name = info->entries[middle].name;

        rc = QPAK_strncmp(path, name, dlen);

        if (rc == 0)

        {

            char ch = name[dlen];

            if (ch < '/') /* make sure this isn't just a substr match. */

                rc = -1;

            else if (ch > '/')

                rc = 1;

            else 

            {

                if (stop_on_first_find) /* Just checking dir's existance? */

                    return middle;

                if (name[dlen + 1] == '\0') /* Skip initial dir entry. */

                    return (middle + 1);

                /* there might be more entries earlier in the list. */

                retval = middle;

                hi = middle - 1;

            } /* else */

        } /* if */

        if (rc > 0)

            lo = middle + 1;

        else

            hi = middle - 1;

    } /* while */

    return retval;

} /* qpak_find_start_of_dir */

/*

 * Moved to seperate function so we can use alloca then immediately throw

 *  away the allocated stack space...

 */

static void doEnumCallback(PHYSFS_EnumFilesCallback cb, void *callbackdata,

                           const char *odir, const char *str, PHYSFS_sint32 ln)

{

    char *newstr = __PHYSFS_smallAlloc(ln + 1);

    if (newstr == NULL)

        return;

    memcpy(newstr, str, ln);

    newstr[ln] = '\0';

    cb(callbackdata, odir, newstr);

    __PHYSFS_smallFree(newstr);

} /* doEnumCallback */

static void QPAK_enumerateFiles(dvoid *opaque, const char *dname,

                                int omitSymLinks, PHYSFS_EnumFilesCallback cb,

                                const char *origdir, void *callbackdata)

{

    QPAKinfo *info = ((QPAKinfo *) opaque);

    PHYSFS_sint32 dlen, dlen_inc, max, i;

    i = qpak_find_start_of_dir(info, dname, 0);

    if (i == -1)  /* no such directory. */

        return;

    dlen = strlen(dname);

    if ((dlen > 0) && (dname[dlen - 1] == '/')) /* ignore trailing slash. */

        dlen--;

    dlen_inc = ((dlen > 0) ? 1 : 0) + dlen;

    max = (PHYSFS_sint32) info->entryCount;

    while (i < max)

    {

        char *add;

        char *ptr;

        PHYSFS_sint32 ln;

        char *e = info->entries[i].name;

        if ((dlen) && ((QPAK_strncmp(e, dname, dlen)) || (e[dlen] != '/')))

            break;  /* past end of this dir; we're done. */

        add = e + dlen_inc;

        ptr = strchr(add, '/');

        ln = (PHYSFS_sint32) ((ptr) ? ptr-add : strlen(add));

        doEnumCallback(cb, callbackdata, origdir, add, ln);

        ln += dlen_inc;  /* point past entry to children... */

        /* increment counter and skip children of subdirs... */

        while ((++i < max) && (ptr != NULL))

        {

            char *e_new = info->entries[i].name;

            if ((QPAK_strncmp(e, e_new, ln) != 0) || (e_new[ln] != '/'))

                break;

        } /* while */

    } /* while */

} /* QPAK_enumerateFiles */

/*

 * This will find the QPAKentry associated with a path in platform-independent

 *  notation. Directories don't have QPAKentries associated with them, but 

 *  (*isDir) will be set to non-zero if a dir was hit.

 */

static QPAKentry *qpak_find_entry(const QPAKinfo *info, const char *path,

                                  int *isDir)

{

    QPAKentry *a = info->entries;

    PHYSFS_sint32 pathlen = strlen(path);

    PHYSFS_sint32 lo = 0;

    PHYSFS_sint32 hi = (PHYSFS_sint32) (info->entryCount - 1);

    PHYSFS_sint32 middle;

    const char *thispath = NULL;

    int rc;

    while (lo <= hi)

    {

        middle = lo + ((hi - lo) / 2);

        thispath = a[middle].name;

        rc = QPAK_strncmp(path, thispath, pathlen);

        if (rc > 0)

            lo = middle + 1;

        else if (rc < 0)

            hi = middle - 1;

        else /* substring match...might be dir or entry or nothing. */

        {

            if (isDir != NULL)

            {

                *isDir = (thispath[pathlen] == '/');

                if (*isDir)

                    return NULL;

            } /* if */

            if (thispath[pathlen] == '\0') /* found entry? */

                return &a[middle];

            else

                hi = middle - 1;  /* adjust search params, try again. */

        } /* if */

    } /* while */

    if (isDir != NULL)

        *isDir = 0;

    BAIL_MACRO(ERR_NO_SUCH_FILE, NULL);

} /* qpak_find_entry */

static PHYSFS_Io *QPAK_openRead(dvoid *opaque, const char *fnm, int *fileExists)

{

    PHYSFS_Io *io = NULL;

    QPAKinfo *info = ((QPAKinfo *) opaque);

    QPAKfileinfo *finfo;

    QPAKentry *entry;

    int isDir;

    entry = qpak_find_entry(info, fnm, &isDir);

    *fileExists = ((entry != NULL) || (isDir));

    BAIL_IF_MACRO(isDir, ERR_NOT_A_FILE, NULL);

    BAIL_IF_MACRO(entry == NULL, ERR_NO_SUCH_FILE, NULL);

    finfo = (QPAKfileinfo *) allocator.Malloc(sizeof (QPAKfileinfo));

    BAIL_IF_MACRO(finfo == NULL, ERR_OUT_OF_MEMORY, NULL);

    finfo->io = info->io->duplicate(info->io);

    GOTO_IF_MACRO(finfo->io == NULL, NULL, QPAK_openRead_failed);

    if (!finfo->io->seek(finfo->io, entry->startPos))

        GOTO_MACRO(NULL, QPAK_openRead_failed);

    finfo->curPos = 0;

    finfo->entry = entry;

    io = (PHYSFS_Io *) allocator.Malloc(sizeof (PHYSFS_Io));

    GOTO_IF_MACRO(io == NULL, ERR_OUT_OF_MEMORY, QPAK_openRead_failed);

    memcpy(io, &QPAK_Io, sizeof (PHYSFS_Io));

    io->opaque = finfo;

    return io;

QPAK_openRead_failed:

    if (finfo != NULL)

    {

        if (finfo->io != NULL)

            finfo->io->destroy(finfo->io);

        allocator.Free(finfo);

    } /* if */

    if (io != NULL)

        allocator.Free(io);

    return NULL;

} /* QPAK_openRead */

static PHYSFS_Io *QPAK_openWrite(dvoid *opaque, const char *name)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);

} /* QPAK_openWrite */

static PHYSFS_Io *QPAK_openAppend(dvoid *opaque, const char *name)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);